Remove Obsolete AddOEmbedProvider extension method

[erikjanwestendorp]

Prerequisites

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Description

Remove AddOEmbedProvider extension method because it should have been removed in v10. Not sure if this should go to v10 or v11 branch now? 😄

[github-actions]

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[nathanwoulfe]

Hi @erikjanwestendorp I'd be inclined to leave this for 11 - while it's obsolete and marked for v10 removal, it shipped in 10, so could still be in use. If we remove it now, it would be a breaking change in v10.1.

Happy to take @bergmania's advice on this one and remove it now if that's deemed ok

[bergmania]

We need to postpone the removal to v11. IIRC it was obsoleted in v9.

[erikjanwestendorp]

@nathanwoulfe @bergmania I see the method has already been removed in v11. My bad 🙈 . Just updated the obsolete message now.